This invention relates to rotary die cutters.
It is necessary with rotary die cutters to provide a means whereby the cut waste is ejected from the cutting rules at a predetermined location since if it is not ejected, or only partially ejected, from a cutting rule then on the next occasion on which that cutting rule is required to effect a cutting action it will either fail to penetrate the board or will only partially do so, resulting in waste and possibly machine downtime.
As is well known to those skilled in the art a rotary die cutter generally comprises a rotary soft anvil and a rotary hard anvil, both of cylindrical form and driven in counter-rotation to assist movement of board to be cut therebetween. Cutting rules are mounted on the cylindrical surface of the hard anvil in an arrangement predetermined by the required final configuration of board. A known means of ensuring ejection of cut waste board out of the cutting rules comprises a series of rods disposed inside the cutting forme, which has an eccentrically-located roller housed therein with the cylindrical surface of the anvil being traversed by an array of holes through which the rods extend when acted upon by the eccentric roller.
With this construction, when the arrangement of cutting rules is set up on the exterior cylindrical surface of the hard anvil it is then necessary to provide an arrangement of the rods within the hard anvil to act within the areas defined by the cutting rules due to the presence of the eccentric roller so that they move outwardly of the cutting forme to eject cut waste board out of the rules only at a predetermined location. The inner ends of the rods are, of course, restrained into contact with the surface of the eccentric roller.
It will be manifest that such a cutting forme is relatively expensive to provide, requires a skilled operator to set up, and involves considerable setting-up time with consequent machine downtime.